1. Field of the Invention
This invention relates generally to mechanical computers for registering the volume of liquid of fuel dispensed by a metering pump as well as the total price of the delivered fuel resultant from a preselected unit price per volume setting.
2. Description of the Prior Art
Mechanical computer-register devices have long been employed for determining and displaying the amount of fuel delivered from a metering pump together with the cost of the delivered fuel commensurate with the unit price per volume of the fuel.
U.S. Pat. No. 3,413,867 issued to R. B. Hamlin, and U.S. Pat. No. 3,677,466 issued to Henri Soupenne disclose such devices which may be selectively set to compute and display a total cost of delivered fuel with the unit price variable from 00.0 to 99.9 cents per gallon.
Such mechanical computer devices consist basically of three differential gear train assemblies arranged in series. Each individual differential gear train assembly consists of a central input gear, a ring gear driven at a variable, settable ratio from 0 to 9, on each ring gear there being compound planet gears with the first gear of the compound gear engaging the central input gear and the second gear engaging a central output gear. Thus, the output gear speed of each differential assembly is the additive total of the speed of the input gear and the speed of the ring gear. Since the output gear of each differential is also the input gear of the succeeding differential and the settable ratios driving the ring gear of each differential may be made a factor of 10 times the preceeding ring gear drive, then the final output gear of the third differential can represent a mulitplication of 0 to 999 times the speed of the first differential input gear.
The rapidly escalating price of gasoline has obsoleted such a price range and necessitates an expanded capability of such computers to enable the calculation of costs based on unit prices extending into the one and two dollar per gallon range. Since the original mechanisms employed only three separate, settable, variable, take off gear or range arm assemblies, one adjustable for 0 to 0.9 cents per gallon, a second adjustable for 0-9 cents per gallon and the third adjustable for 0-90 cents per gallon, then their totalizing capacities were limited to a maximum price range of 99.9 cents per gallon. In order to convert from a three place to a four place computer, it is necessary to add a fourth differential mechanism.
Prior art U.S. Pat. No. 3,875,816 of Arthur James Wells and U.S. Pat. No. 4,136,573 of Bruno Smilygs et al. disclose conversion means to extend this price range above 99.9 cents per gallon. The present invention discloses an alternate method of achieving this extended price range.